It's Thursday, so that means it's time for Thursday thoughts. If you did not catch my post last Thursday, I decided to start this new segment where I share my thoughts on a nutrition of health related topic, based on my observations and experience in practice, and when available, scientific evidence.

This week, I want to share my thoughts on a topic Ryan and I were discussing last week. The first time this came up, I was living in Vegas still and having a conversation with another dietitian and the answer seemed very obvious to us as dietitians. The issue I am I talking about is high fructose corn syrup (HFCS) and obesity.

Causation is very hard to prove, and most research looks at links, not causes. For someone to say HFCS is the reason so many people are obese, is a huge overgeneralization. There are too many factors missing from this equation.

But people still notice when they cut all HFCS from the diet, they lose weight, leading them to believe, this is the cause for obesity. So let's look at some of the possible reasons for this.

1) Cutting anything out from the diet means you are more vigilant over what you put into your body. As Ryan mentioned when we were discussing this, it forces you to have to read labels and watch what you eat. You are more likely to eat less calories just because you are forced to make better food choices and review labels. You are just more aware of what you are eating.

2) Along the lines of the first thought, it is almost like a fad diet in theory. One item is eliminated, and it forces everything else to be monitored. When monitoring intake, like on a fad diet, people are rigid in following guidelines, and they often are very into their new diet plan and overly excited at the start. By cutting back on food intake in general, weight is lost. The weight loss equation is energy in vs energy out and when in balance, weight is maintained. So focusing on what you are eating, almost always lead to less caloric intake than usual.

3) Think about the foods that contain HFCS. Not only are these high in added sugars, they are often high in fat as well, meaning calories add up quickly. Eliminating HFCS almost immediately eliminates all sweets and junk foods. The end result is a reduction in calories, which leads to weight loss. By cutting out HFCS it will drastically alter the foods available for a person to consume on a daily basis, and many will be lower calorie options.

4) That brings me to my next point. When someone is left to choose whole gains and produce more often, they are likely increasing their fiber intake too. Chances are this is helping with satiety and keeping them feeling fuller for a longer period of time, thus contributing to less caloric intake for the day.

5) Could HFCS contribute to obesity? Sure it can. It does when coupled with excess calories for the day. But, there is little evidence that eating a diet with less calories than you need, and that contains HFCS, a person will still be obese. Just looking at HFCS is an error because there are too many other variables that are not accounted for. There is more to the energy balance equation than just HFCS. In fact, the body really can't distinguish between the kinds of sugar you eat. The body does not realize if it is HFCS, honey, table sugar, lactose or fructose, although the body does have to digest them a little differently in order to obtain glucose from the molecules for energy use in the body. As Dr. Willett write in his book Eat, Drink, and Be Healthy, the structure of sucrose (table sugar) is a glucose molecule and a fructose molecule, and HFCS is glucose, with almost equal parts fructose, making the two molecules almost identical. I am going to go with Dr. Willet on this one. He is the leader in nutritional epidemiology research (yes, the field I wish to complete my PhD in one day). Since the body is not going to differentiate, it is unlikely that HFCS is any worse than regular table sugar. Everything in moderation. Too much table sugar, too much HFCS, and too much of anything when it comes to calories will lead to weight gain.

Well, there you have it...my thoughts on HFCS as the cause for obesity. Obesity is more complex than just one factor. People caused the obesity epidemic. Everyone has a choice, and unfortunately poor choices can be made when someone is not educated on the situation. Poor choices by consumers, in my opinion, led to more undesirable products hitting the market. The lack of knowledge led people to purchase these products, and while food companies and marketing firms may have "tricked" people, it was the consumers in the end who created a need for certain foods products, and things really got out of hand. Again, I think mostly because of a lack of education, and asdly, companies took advantage of this. i also think some food companies may not have really known how bad something would be for a person because they could not predict a lack of ability to monitor portion sizes consumed in one sitting.

Nutrition science is a new science, dating back really only until the early 1900's, so it is still evolving and we are still learning and identifying components. It would also help if the media promoted more truths and less fads, but I assume that is just more boring and we all know the mass media outlets are anything but boring.

QUESTIONS: Have you heard people say before that they feel HFCS caused the obesity epidemic? Or do you personally feel that HFCS is the cause for obesity? Any topics you would like me to weigh in on for future installments of Thursday Thoughts?

9 comments:

I like hearing your opinions on contraversial topics. I agree with you. No HFCS isn't good for you, and I try to limit the processed foods I eat to avoid it. But I don't think that somethings as complex as the obesity epidemic can be blamed on one thing. There are too many factors at work.

Great post Melinda. This topic can really get me going and you've pinpointed the exact arguments I have. I can't stand it when people tell me "HFCS caused the obesity epidemic". And trust me, I hear this a lot (I'm sure you know....). In my opinion that's a very naive statement!

great post! I completely agree, there's so much more complex issues going on, not just HFCS. And what about agave with even more fructose? but that isn't getting the blame because it's not in every single thing and 'natural'! Also I'm not so sure I agree with the corn subsidies either.

Loved this post, Melinda. I love your grounded, fair-minded view on this. It's just human nature to demonize things, and categorize in extreme ends. I don't think HFCS is healthy of course, but the bad rep it gets is shifting focus away from other more important details that causes this obesity epidemic.

I love that you are doing a "Thursday Thoughts" series! Great post! I think we have a tendency to look for things to blame and "easily fix." You are so right, HFCS is not the only reason people are obese; it's a very complex issue. And you are right, if someone cuts all HFCS out of his/her diet, the person is probably changing his/her diet very drastically and weight loss occurs for many reasons. I think by focusing on one "evil ingredient," we often miss the bigger picture. (BTW, the same is true for "super healthy foods" in my opinion.)

I think it's a good idea for people to cut back on HFCS and focus on unprocessed foods, especially fruits and veggies. It's also a good idea to make/bake/cook as many foods as we can from scratch. However, personally, I don't worry too much if I consume a bit of HFCS once in a while...

I think this is a great topic, Melinda - thank you for focusing on it, and pointing out that it's VERY hard to prove causality in nutrition, obesity, and disease, especially when you're looking at individual foods rather than dietary patterns.

Much of the hoopla and villification of HFCS is due to its ubiquitous presence as a cheap sweetener. If HFCS did not exist, some other sweetener (or fat, or ...) would be villified instead. Which tells you sometimes about where we place our blame rather than about the foods themselves. It's great that you emphasize how sugar and HFCS or any sweetener contribute to obesity equally.

Ohhhh! Mel, I am totally loving your thoughts. Seriously, I am super impressed here. Okay...have you watched FOOD INC? I've read all of Michael Pollan's books and one thing I am now committing to: 2 processed foods per grocery visit, per week. Today, I made homemade granola bars rather than buying premade. And I've cut down on buying cereal (one a week, usually Kashi or Organic Flakes. Why? Because I want to see 80% of my foods that are living...not immune to being "dead" and that is what HCF does...it makes something super artificially sweet and last longer. Do a post on how it is in EVERY granola bar, loaf of bread, cereal box....WOW, huh? Want to know why???? MONEY!